United States Environmental Protection Agency Municipal Environmental Research Laboratory Cincinnati OH 45268 Research and Development EPA-600/S2-81-213 Oct. 1981 Project Summary Feasibility of Commercialized Water Treatment Techniques for Concentrated Waste Spills M. Ghassemi, K. Yu, and S. Quinlivan The suitability and economics of using commercial water treatment techniques for onsite treatment of concentrated wastes were evaluated. The techniques included reverse osmosis, ultrafiltration, ion exchange, wet-air oxidation, high-purity oxygen- activated sludge process, ultraviolet- ozone oxidation, and coagulation/pre- cipitation. Data from the published literature and those obtained from process suppliers provided the basis for the evaluation. When used alone, none of the pro- cesses considered would be econo- mically applicable to onsite mobile unit treatment of the variety of concentrated wastes encountered, although reverse osmosis, ion ex- change, and wet-air oxidation meet many of the application requirements and, hence, require less pretreatment, or post-treatment. The estimated capital costs for a unit suitable for trailer mounting vary from as low as $35,000 for a 227,000-L/day (60,000-gpd) ultrafiltration unit to as high as $1.25 to $1.5 million for a 54,000-L/day (14,400-gpd), two- trailer, wet-air oxidation unit. For short-term operation, the operating cost of the mobile unit is determined largely by nonprocess-specific costs (e.g., transportation, labor, subsis- tence, analytical support), which vary from situation to situation. This Project Summary was devel- oped by EPA's Municipal Environ- mental Research Laboratory, Cincin- nati, OH, to announce key findings of the research project that is fully documented in a separate report of the same title (see Project Report ordering information at back). Introduction and Study Objectives In recent years, considerable efforts have been directed by government and the private industry toward developing emergency response capabilities for the treatment of waters containing high concentrations of contaminants that are encountered in hazardous material spill situations and at uncontrolled waste disposal sites. The U.S. Environmental Protection Agency's (EPA) Environ- mental Emergency Response Unit (EERU) is currently engaged in the shakedown and field demonstration of a number of EPA-developed wastewater treatment equipment and techniques for use in emergency situations. The EERU's Mobile Flocculation-Sedimenta- tion System and Mobile Physical- Chemical Treatment Trailers have been successfully used to facilitate cleanup operations at several uncontrolled waste disposal and hazardous materials spill sites. A number of other systems, including the Mobile Incineration System, Mobile Independent Physical-Chemical Wastewater Treatment System, Mobile System for Detoxification/Regeneration of Spent Activated Carbon, and Mobile Reverse Osmosis Treatment System, are also currently in various stages of development and testing. ------- In mobile unit applications involving highly concentrated organic wastes (TOC and COD levels exceeding 4,000 to 5,000 mg/L), the conventional physical- chemical treatment systems employing chemical coagulation/flocculation, filtration, and activated carbon adsorp- tion have to be very costly. Hence, a need exists for the development of more economical alternatives for onsite treatment of concentrated wastes. The study summarized here evaluates the suitability and economics of several commercially available water and wastewater treatment processes for use in mobile units for onsite treatment of highly contaminated waters. Processes Evaluated and Evaluation Criteria Seven processes were evaluated for onsite treatment of concentrated wastes in mobile units.* These processes, which are briefly described in Table 1, are: reverse osmosis (RO), ultrafiltration (UF), ion exchange (IE), wet-air oxidation (WAO), high-purity oxygen-activated sludge process (HPOASP), UV-ozone *To make the study more complete, gravity separation, filtration, activated carbon adsorption, and incineration (which have been used or are under development for spill control applications) were also briefly reviewed. These reviews, however, are not included in this Project Summary. oxidation (UV/03), and coagulation/ precipitation (CP). The process evaluation has been based on the published literature and data obtained from process and equip- ment suppliers. The study has generally assumed the use of a single trailer or 227,000-L/day (60,000-gpd or 42-gpm) hydraulic capacity and the use of a process alone rather than in combina- tion with other processes in a treatment train. The process evaluation has been in terms of general process capabilities and limitations, suitability for the removal of certain pollutant types (TOC/COD, heavy metals, oily sub- stances, etc.), and capital and operating costs for a mobile unit handling a hypothetical concentrated waste. General Process Capabilities and Limitations Table 1 presents brief descriptions of the processes reviewed and a general and qualitative assessment of their capabilities and limitations in terms of commercial experience and applicability to diverse waste types (including con- centrated wastes). As noted in Table 1 'Mention of trade names or commercial products does not constitute endorsement or recommenda- tion for use. (with the exception of UF and UV/03, for which full-scale commercial application experience is somewhat limited), the processes considered are widely used commercially in a range of applications involving water and wastewater treat- ment. Processes that are suitable and have been used commercially for the treatment of concentrated wastewaters areRO, UF, IE, and WAO. The remaining three processes are not suitable for treatment of concentrated wastes be- cause of the long detention time (reactor size) required for HPOASP, the produc- tion of a large volume of bulky sludge in CP, and reduced efficiency and high ozone requirement in UV/0. Table 2 reviews the extent of previous use in mobile units and the limitations and desirable features for such a use for each of the processes considered. RO, IE, and HPOASP have been used in mobile units of various designs for wastewater treatability studies. A 2,300-L/hr (10-gpm) WAO mobile unit, currently under design by Zimpro,* is expected to be available for use in waste treatability studies in 1981. UV/03 and UF systems have not been used in mobile units. CP has been used in connection with physical/chemical treatment in mobile units. | RO and IE processes appear to meet" many of the requirements for applica- Table 1. Description of Processes Reviewed and Their General Capabilities and Limitations Process RO Major developers/suppliers Description Aqua Media (Sunnyvale, CA) Use of high pressure to force Limitations Membrane fouling/ degrada- Commercial experience with full-scale units More than 300 units in Experience with and applicability to concentrated wastes Industrial wastewaters UF IE Dow (Walnut Creek, CA) solvent (for example, water) Envirogenics (El Monte, CA) through a membrane permeable Fluid Systems Div/UOP (San Diego, CA) Hydranautics (Santa Barbara, CAI Permutit (Paramus, NJ) Polymetric (San Jose, CA) to solvent but not the solute. Several membrane types and designs available Abcor (Wilmington, MA) Envirogenics (El Monte, CA) Fluid Systems Div/UOP (San Diego. CA) Osmonics (Hopkins, MN) Romicon (Woburn, MA) Chemical Separation Corp. (Oak Ridge. TN) Crane Co. (King of Prussia, PA) Ecodyne (Union, NJ) Illinois Water Treatment (Rockford, IL) Infilco (Richmond, VA) Permutit (Paramus, NJ) Pressure-driven membrane separation process operating at a lower pressure than RO and suitable for separation/con- centration of large molecular weight substances. Several membrane types and designs available. Replacement of toxic/undesir- able ions in waste with harmless ions "attached" to exchange resins. "Sorptive" resins remove organics via adsorption. Resins employed in columnar beds and regenerated with acid, alkali or salt solutions. Sorptive resins also eluted with organic solvents. tion by suspended solids, biological growth, strong oxi- dizers, very low/high pH, and high concentration of speci- fic substances (for example, phenols, calcium, silica. sulfate, aluminum). Reject requires further treatment/ disposal Membrane fouling/degrada- tion similar to RO but to a lesser extent. For wastes containing high levels of low molecular weight sub- stances, effluent may require additional treat- ment. Rejects require further treatment/disposal Pretreatment for suspended solids removal may be necessary for longer service. Very concentrated waste may require frequent resin regeneration. Residue requires further treatment/ disposal. operation demineralizing brackish waters. Used for treatment of industrial wastewaters (for example. plating rinses, cooling tower blowdown, petroleum stripping water) and in in- dustrial applications (for example, food processing) Separation and concentra- tion of macromolecules from dilute industrial process/waste streams. Full scale units in operation in food pro- cessing, textile and metal cutting industries. Widely used for water softening and boiler water treatment. Used in industry for material recovery from and/or treatment of wastewaters from electro- plating industry and muni- tions, fertilizers, dye- stuff, pesticides, chlorine, and resins production. containing several thousand ppm TDS, as well as sea water (3 5% TDS) successfully treated. Feed solid concentration as high as 46,300 ppm handled. A latex waste averaging 21.000 ppm COD, 3.500 ppm oil and grease and 1,600 ppm TSS successfully treated in a 20.0OO gpd unit. Commercially used for phenol recovery from concentrated (—20%) brine and removal of color and organics from pulp mill effluents. ------- Table 1. (Continued! Process Major developers/suppliers Description Limitations Commercial experience with full-scale units Experience with and applicability to concentrated wastes WAO Zimpro (Rothschild. Wl) Aqueous phase oxidation of re- duced inorganic and organic substances with air at high temperatures (ZOO to 320°C) and pressures (150 to 4,000 psi). Process specially suitable for treatment of high strength or toxic/refractory organic wastes. HPOASP UV/0, CP Westgate Research Corp. fW. Los Angeles, CA) Numerous Requirements for skilled operators (especially for hazardous wastes/ and special design and con- struction materials. Air Products and Chemicals (Allentown. PA) Union Carbide (Tonawanda, NY) High purity (90-100%v) oxygen Inapplicable to wastes high is fed to a mixed covered in toxic, volatile, or re- reactor in which microorganisms fractory substances or having low or high pH. Long detention time (large reactor size) required for concentrated wastes. Con- siderable time required for process start-up. Nutrient addition and pH adjustment may be necessary. Use of UV and ozone to destroy/ New process, not suitable in the wastewater convert dissolved and oxidizable organics to inorganic end pro- ducts and to agglomerating and settleable floes. More than 150 units in operation worldwide; about 90% handling municipal sludges. Also used for treatment of cyanide. pulp and paper, photo- graphic and glue manufac- turing wastes. Numerous full-scale units in operation handling municipal and industrial wastewaters. Examples of industrial applications are treatment of brewery, citrus and chemical plant wastes. Nearly all large applications have been for treatment of sludges and concen- trated organic wastes. The most concentrated chemical waste treated without pretreatment has a COD value of 1,000 to 3,000 ppm. oxidize organics (including refractory and toxic chemicals), organometallic complexes and reduced inorganics. Addition of chemicals (alkali, sutfide, and aluminum/ferric salts) to precipitate dissolved substances and to coagulate suspended solids. for wastes high in organics or suspended solids, re- quirement for on-site Oa generation, and release of some residual Oa to air. Ineffective for removing a spectrum of dissolved organic and inorganic substances. Optimum pH and chemical dosage vary with wastes. Large volume of bulky sludge produced with concentrated wastes. Very limited. Two plants reportedly in operation handling photographic, metal plating and cyanide wastes at any Army ammuni- tion plant and a tool production plant. Extensively used for treatment of municipal/ industrial water supplies. Widely used in conjunction with other wastewater treatment processes. Not suitable for con- centrated wastes. Not suitable for con- centrated wastes. Table 2. Mobile Unit Experience and Process Features for Mobile Unit Application Features for mobile unit use Process Mobile unit experience Desirable features Limitations RO Several 10,000 to 50,000 gpd trailer-mounted units operated for obtaining potable water from brackish waters. UF None. Skit mounted units (5,000 to 10,000 gpd suitable for trailer mounting available). IE Trailer-mounted units have been used in field pilot plant studies in- volving treatment of biologically-treated sewage and wastewaters at a munitions plant and a naval installation. Compact and modular units, quick startup and shutdown, conveniently serviced, not requiring skilled operators, operable with power generated on-site with diesel generator, small residue volume (10 to 25 percent of influent volume). Same as RO. Same as for RO plus ease of auto- mation, applicable to a range of waste types and concentrations (including those having low or high pH and oxidizing chemicals) by proper selection of resin types and system design/operation. Volume of residue seldom exceeding 10 percent of influent. See general limitations in Table 1. See general limitations in Table 1. See general limitations in Table 1. ------- Table 2. (Continued) Process Mobile unit experience Features for mobile unit use Desirable features Limitations WAO None. A 0.1 gpm trailer- mounted unit used at process developer's site for waste treatability studies. A 10 gpm 2-trailer unit under design. HPOASP Process suppliers have several mobile units used for waste treata- bility studies. UV/03 None. CP Used by EPA in conjunc- tion with settling and filtration and activated carbon adsorption for treatment of spills and concentrated wastes from uncontrolled chemical dump sites. Suitable for treatment of a range of oxidizable wastes. No air pollution problem. Innocuous residue from most organic wastes. Suitable for treatment of readily biodegradable non-toxic wastes. Compact and modular units, quick startup/shutdown, conveniently serviced, not requiring skilled operators, operable with on- site generated power from a die set generator. Wide variety of chemical feeding and metering devices available commercially. General limitations in Table 1 plus size/weight limitations. 10 gpm is the largest unit which can be trailer-mounted (on 2 trailers). Supplemen- tary heating necessary for low-Btu wastes. General limitations in Table 1 plus size/weight limitations and slow startup. Based on a maximum reactor size of 12,500 gal suitable for trailer mounting and a detention time of 48 hr (for a waste COD of 1,000 to 3,000 ppm), hydraulic capacity would be 4 gpm. See general limitations in Table 1. See general limitations in Table 1. bility to the treatment of concentrated waste in a mobile unit. These processes offer compact units that can be started and shut down relatively quickly, can be serviced conveniently, would not require skilled operating field labor, can be operated with electricity produced by on-board generators, can handle a spectrum of wastes including those containing high concentrations of toxic substances and refractory organics, and can produce a relatively small volume of waste residue requiring disposal. WAO, which is particularly applicable to the destruction of refractory and toxic organics in concentrated wastes, has the limitations of small capacity and the requirement for skilled operators. UF suffers from the limitation of inapplica- bility to wastes containing low-molec- ular-weight substances, whereas highly concentrated, large-volume wastes cannot be processed by UV/03, HPOASP, and CP. When used alone, none of the processes considered would meet all the requirements for use in mobile units for treatment of concentrated wastes. The applicability of these processes would be enhanced (and the treatment costs would be reduced), however, if these processes were used in combina- tion in a treatment train. The specific process combinations that would be applicable to the types of wastes en- countered in spill situations and at uncontrolled chemical dump sites re- main to be evaluated. Comparison of Processes for Reducing Specific Pollutant Categories Table 3 summarizes and compares the capabilities of the various processes considered for the treatment of high- strength wastes. For discussion pur- poses, the following raw wastewater gross characteristics/constituent levels (which are typical of concentrated wastes encountered in spill situations and at uncontrolled hazardous waste disposal sites) have been assumed: TOC: 5,000 mg/L COD: 8,000 mg/L Low-molecular-weight organic substances not removable by activated carbon: Present Oily substances: 300 mg/L SS: 1,000 mg/L Heavy metals: 200 mg/L pH: 4-5 Based on the performance data in Table 3, none of the processes considered would be able to handle a waste stream with the above characteristics without some pretreatment. But, when properly designed and operated, RO, IE, and WAO should require less pretreatment and post-treatment than other processes considered. Pretreatment required with RO and IE would be primarily for the removal of suspended solids and can be accomplished by chemical coagulation and settling, or filtration, or both. WAO is not expected to effect heavy met removal. The present engineering an -\W stal \ ------- Table 3. Comparison of Process Capabilities for Reduction of Indicated Constituents/Parameters Proce TOC/COD Low molecular weight organics Oily substances SS Heavy metals Reverse osmosis Uftraftltration Generally greater than 90%. Greater than 90% for large molecular weight organics Varies with the species and wastewater pH Removal generally decreases with in- crease in polarity and ten- dency for hydrogen bonding with membrane Ineffective for removal of low molecular weight substances Greater than 9O% Greater than 90% Pretreatment to lower SS load necessary to prevent membrane fouling and maintain high flux. Some pretreatment to lower SS necessary to extend membrane life and maintain high flux Greater than 90% removal of ionic species, including most heavy metals. Ineffective, because of low molecular size. Ion exchange Wet air oxidation High purity oxygen activated sluge process Ultraviolet-ozone oxidation Coagulation/ precipitation Almost any degree of re- moval can be obtained with the use of sorptive resins. proper design and operating conditions {including pH adjustments) Greater than 90%, depending on operating conditions Little or no removal if organics are toxic or re- fractory or if waste con- tains a high concentration of toxic inorganics Unless waste is diluted. very long detention time would be required to achieve high removal Percent destruction limited by ozone supply capacity Ineffective for removal of most organics; use of high chemical doses pro- duces large volume of sludges which are difficult to process and dispose of Can remove low molecular weight organics, removal efficiency dependent on design and operating conditions Very high destruction efficiency, achievable by proper selection of operating conditions. Removal efficiency deter- mined by biodegradability and lack of toxicity, and not molecular weight per se Molecular weight per se not a factor in process efficiency Generally ineffective Must be removed to extend resin life. Very high destruc- tion efficiency. achievable by proper selection of operating con- ditions. Greater than 60%, if other condi- tions are proper for biooxidation Should be removed to minimize inter- ference with light transmission Can effect removal of separable oils; 30-40% removal can be expected under proper pH and dosage Pretreatment to lower SS necessary to prevent bed clogging Organic SS can be destroyed Prior settling and removal of SS desirable to improve process efficiency Should be removed to mini- mize interference with light transmission. When followed by settling/ filtration and under proper pH and dose condi- tions can effect more than 9O% removal. Can remove all charged species, including heavy metals Ineffective in removing in- organics, can destroy heavy metal-organic complexes so that heavy metals can be subsequently removed. Heavy metals can exert toxic effects Does not remove heavy metals; destroys metal- organic complexes so that heavy metals can be removed subsequently. Addition of hydroxide, sulfide, phosphate, etc.. can effect near complete removal of many heavy metal cations ysisdid not include comparative assess- ment of various possible process combinations to identify promising and cost-effective treatment schemes in- cluding the use of two or more trailers housing different processes and process combinations. For example, WAO may be used to handle the smaller volumes of more concentrated residues resulting from the other processes and process combinations. Estimated Costs Table 4 presents the estimated capital costs for a unit suitable for installation on a flat-bed trailer. The estimated costs vary from as low as $35,000 for a 227,000-L/day UF unit to as high as $1.25 to $1.5 million for a 54,000- L/day, two-trailer WAO unit. As noted in Table 4, there are differences in labor type, materials, and fuel requirements for the operation of various processes. But in most, especially the short-dura- tion, applications, these differences should not have a significant impact on the overall operating cost of the mobile unit. The latter is determined largely by nonprocess-specific costs such as the fixed cost for transportation, startup, and shutdown of the mobile unit; equip- ment insurance; labor; subsistence; and general analytical support. EPA's ex- perience with the operation of the Mobile Physical/Chemical Treatment System indicates a nonprocess-specific fixed cost of about $ 10,000, a cost for one charge of carbon of $10,000 to $12,000 per deployment, and an oper- ating cost of $2,500 to $3,000 per day. The full report was submitted in fulfillment of Contract No. 68-03-2560 by TRW Environmental Engineering Division, Redondo Beach, California 90278, under the sponsorship of the U.S. Environmental Protection Agency. ------- Table 4. Estimated Capital Cost and Operating Fuel, Labor Category and Chemical Requirements Process Reverse osmosis Ultrafiltration Ion exchange Capital cost*, $ 75,000% 35,000 140,000 Energy requirement L of fuel/1, 000 L of waste 11 2 1 Labor category requirement^ Semi-skilled; 4 to 12 hrs per 24 hr operation Semi-skilled; 4 to 12 hrs per 24 hr operation Skilled; 4 to 12 hrs per 24 hr operation General chemicals and materials requirement^ Acid or base for pH adjustment- scale inhibitors and biocides Acid or base for pH adjustment; scale inhibitors and biocides 1 to 3 bed volumes of acid and base (5 to 10 percent solution) Wet air oxidation High purity oxygen activated sludge process Ultraviolet-ozone oxidation Coagulation/ precipitation 1.250,000 to 230 Highly skilled; 4 to 12 hrs 1,500,000 per 24 hr operation 200,000 1 Skilled; 1 full time operator 285,000 50 Semi-skilled; 2 to 6 hrs per 24 hr operation — 1 Semi-skilled; 4 to 12 hrs per 24 hr operation required for each regeneration; organic solvents (for example, methanol or acetone) may be required for regeneration of sorptive bed Acid or base for pH adjustment; nitrogen and phosphorus as sup- plemental nutrients; high purity oxygen Replacement of UV lamps Coagulant salts; acid or base for pH adjustment *Capital costs are for a 227,000 L/day single-trailer unit, except for wet air oxidation which has a capacity of only 54,000 L/day and employs two trailers. To allow process versatility, the ion exchange system is designed with an excess capacity so that a combination of resin types can be used. •\The labor hour estimates are the minimum requirement for operation under "ordinary" conditions. For safety reasons, however, a minimum of 2 persons would be required for field operation. \The specific chemicals and quantities required would depend on the concentration of specific constituents in the waste; accurate estimates cannot be made for the waste considered here since detailed composition were not assumed. §The estimated costs provided by three process suppliers were $55,000, $75,000, and $120,000 to $180,000. M. Ghassemi, K. Yu, and S. Quinlivan are with TRW Environmental Engineering Division, Redondo Beach. CA 90278. Frank Freestone is the EPA Project Officer (see below). The complete report, entitled "Feasibility of Commercialized Water Treatment Techniques for Concentrated Waste Spills," (Order No. PB 82-108 440; Cost: $11.00, subject to change) will be available only from: National Technical Information Service 5285 Port Royal Road Springfield. VA 22161 Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Oil and Hazardous Materials Spills Branch Municipal Environmental Research Laboratory—Cincinnati U.S. Environmental Protection Agency Edison, NJ 08837 ------- United States Environmental Protection Agency Center for Environmental Research Information Cincinnati OH 45268 Postage and Fees Paid Environmental Protection Agency EPA 335 Official Business Penalty for Private Use $300 RETURN POSTAGE GUARANTEED PS 0 U S FNViR PROTECTION RtGIOiN. 5 LIBRARY 230 S AtAKHQRN STREET CHICAGO IL 6060a AGENCY *•!! <; CnUFRNMFNT PRINTINT, n FFT f.E•: ------- |